JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap-theme.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
<input type="text" data-placement="bottom" data-trigger="manual" data-content="" name="momlastname" id="momlastname" ng-model="momlastname" />

JavaScript

(function () {

    function firstCapital(word) {
        return /^[A-Z]/.test(word);
    };


    function NumberOnly(e) {
        var inp = String.fromCharCode(e.which);
        if (/[0-9]/.test(inp)) return true;
        else return false;
    };

    $('#momlastname').keypress(function (f) {

        switch ($(this).val().length) {
            case 1:
                message = "Lower letter";
                break;
            case 10:
                message = "10 characters have been reached";
                break;
        }

        if (NumberOnly(f)) {
            f.preventDefault();
            $('#momlastname').popover({
                trigger: 'manual',
                content: function () {
                    return "Enter text only.  Numbers cannot be entered.";
                }
            });
            $('#momlastname').popover('show');
            $('#momlastname').addClass('error');

        } else if ($(this).val().length == 1 && !firstCapital($(this).val())) {
            $('#momlastname').popover({
                trigger: 'manual',
                content: function () {
                    return message;
                }
            });
            $('#momlastname').popover('show');
            $('#momlastname').addClass('error');
        } else if ($(this).val().length == 70) {
            $('#momlastname').popover({
                trigger: 'manual',
                content: function () {
                    return message;
                }
            });
            $('#momlastname').popover('show');
            $('#momlastname').addClass('error');
        } else {
            $('#momlastname').popover('hide');
            $('#momlastname').removeClass('error');
        }

    });

});